1. Field of the Invention
This invention relates to crystallized glass-ceramic molded products suitable for application to ornamental objects such as furniture, interior or exterior walls, floors, pillars, ceilings or the like of building materials and a method of manufacturing such molded products.
2. Description of Material Information
A conventional crystallized glass-ceramic molded product previously put into practical use has an appearance similar to natural marble of white-color series, and has a structure in which light diffusing white crystals of glasses such as .beta.-wollastonite or the like are produced in a colored or colorless glass matrix. A white colored appearance results.
Thus, there have not been obtained so far any artificial stones having various patterns in the form of spots, streaks, clouds, or other shapes in various colors, and which give the appearance or impression of colors and patterns of natural stones such as marble with blue and white spots or black and white spots; granite with red, blue, black and white spots; agate, granite with light red or cobalt spots, or the like.
In order to produce crystallized glass-ceramic molded products having, as desired, not only the appearance of natural stones, but also the artistic appearance of ones which do not occur in nature, the inventors of this application carried on various research and made an invention as disclosed in Japanese Kokai Patent Publication No. Showa 58-176140. The invention disclosed in the foregoing publication relates to a crystallized glass-ceramic molded product and method for manufacturing the product. According to this prior invention, there can be obtained various products provided with various colors and various patterns as desired, by a method wherein constituent materials for producing conventional glass and constituent materials for producing coloring fluormicas are mixed together and a mixture thereof is heated so as to fuse and the mixture is then cooled and solidified to form frit. Particles of different kinds of frits thus produced are mixed together and molded and then subjected to a sintering treatment and a crystallizing heat-treatment so that crystals of the colored fluormicas are precipitated in the glass matrix. The resultant products have multiple colors and patterns which are produced by reflecting incident light beams projecting into the product from the crystals of the colored fluormicas.
Using this prior invention, there have been developed crystallized glass-ceramic products having multiple colors and patterns. However, the difference between the refractive index (1.51-1.57) of the crystals of fluormica and that (1.49-1.55) of the glass is very small. Additionally, the shape of the fluormica is a thin scale, or flake, and most of the fluormica particles in the product are 0.3-1.0 micron in diameter, the thickness being 1/10-1/30 of the diameter. Consequently, the amount of reflected incident light from the crystals of the fluormica is very small and the amount of light passing therethrough is very large, and accordingly visibility of the multiple colors and patterns of the product is poor. In order to give distinct, visible multi-colors and patterns it is necessary to add a large amount of the constituent materials for producing fluormicas and to increase the amount of fluormicas produced so that incident light may be given multi-reflections by the increased amount of the produced fluormicas.
The fluormicas of the fluorophlogopite system, KMg.sub.3 (AlSi.sub.3 O.sub.10)F.sub.2, which is one of the groups that includes mostly coloring fluormicas, are good in crystallizing out of the constituent materials thereof within the glass in a high temperature range of above 800.degree. C., but poor in a low temperature range of 550.degree.-800.degree. C. In addition, as to the fluormicas of the fluoromuscovite system and those of tetrasilic fluormica system, KMg.sub.2.5 (Si.sub.4 O.sub.10)F.sub.2, crystals thereof can be produced out of the constituent materials thereof but the amount produced is poor.
It is an object of the present invention to improve the prior invention and to provide crystallized glass-ceramic molded products displaying distinct single or multi-colors and various patterned appearances and a method of making the products.